Polishes always contain abrasives. That’s because, in order to shine a dulled surface, a very thin coating of paint or gel coat that has been dulled by weather and time must be removed. The difference 2 products lies entirely in the type of abrasive agent that is used, and the solvents and detergents that are designed to soften the surface in order to remove a thin layer. The shiny look comes from the apparently intact remaining surface layer of paint, as well as such molecules as silicon, or better still, PTFE. In the case of metals, the goal is “rub out” the micro-scratches, and remove the oxidation.